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+//===-- ArchiveWriter.cpp - Write LLVM archive files ----------------------===//
+//
+// The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// Builds up an LLVM archive file (.a) containing LLVM bitcode.
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/Bitcode/Archive.h"
+#include "ArchiveInternals.h"
+#include "llvm/ADT/OwningPtr.h"
+#include "llvm/Bitcode/ReaderWriter.h"
+#include "llvm/IR/Module.h"
+#include "llvm/Support/FileSystem.h"
+#include "llvm/Support/MemoryBuffer.h"
+#include "llvm/Support/Process.h"
+#include "llvm/Support/Signals.h"
+#include "llvm/Support/system_error.h"
+#include <fstream>
+#include <iomanip>
+#include <ostream>
+using namespace llvm;
+
+// Write an integer using variable bit rate encoding. This saves a few bytes
+// per entry in the symbol table.
+static inline void writeInteger(unsigned num, std::ofstream& ARFile) {
+ while (1) {
+ if (num < 0x80) { // done?
+ ARFile << (unsigned char)num;
+ return;
+ }
+
+ // Nope, we are bigger than a character, output the next 7 bits and set the
+ // high bit to say that there is more coming...
+ ARFile << (unsigned char)(0x80 | ((unsigned char)num & 0x7F));
+ num >>= 7; // Shift out 7 bits now...
+ }
+}
+
+// Compute how many bytes are taken by a given VBR encoded value. This is needed
+// to pre-compute the size of the symbol table.
+static inline unsigned numVbrBytes(unsigned num) {
+
+ // Note that the following nested ifs are somewhat equivalent to a binary
+ // search. We split it in half by comparing against 2^14 first. This allows
+ // most reasonable values to be done in 2 comparisons instead of 1 for
+ // small ones and four for large ones. We expect this to access file offsets
+ // in the 2^10 to 2^24 range and symbol lengths in the 2^0 to 2^8 range,
+ // so this approach is reasonable.
+ if (num < 1<<14) {
+ if (num < 1<<7)
+ return 1;
+ else
+ return 2;
+ }
+ if (num < 1<<21)
+ return 3;
+
+ if (num < 1<<28)
+ return 4;
+ return 5; // anything >= 2^28 takes 5 bytes
+}
+
+// Create an empty archive.
+Archive* Archive::CreateEmpty(const sys::Path& FilePath, LLVMContext& C) {
+ Archive* result = new Archive(FilePath, C);
+ return result;
+}
+
+// Fill the ArchiveMemberHeader with the information from a member. If
+// TruncateNames is true, names are flattened to 15 chars or less. The sz field
+// is provided here instead of coming from the mbr because the member might be
+// stored compressed and the compressed size is not the ArchiveMember's size.
+// Furthermore compressed files have negative size fields to identify them as
+// compressed.
+bool
+Archive::fillHeader(const ArchiveMember &mbr, ArchiveMemberHeader& hdr,
+ int sz, bool TruncateNames) const {
+
+ // Set the permissions mode, uid and gid
+ hdr.init();
+ char buffer[32];
+ sprintf(buffer, "%-8o", mbr.getMode());
+ memcpy(hdr.mode,buffer,8);
+ sprintf(buffer, "%-6u", mbr.getUser());
+ memcpy(hdr.uid,buffer,6);
+ sprintf(buffer, "%-6u", mbr.getGroup());
+ memcpy(hdr.gid,buffer,6);
+
+ // Set the last modification date
+ uint64_t secondsSinceEpoch = mbr.getModTime().toEpochTime();
+ sprintf(buffer,"%-12u", unsigned(secondsSinceEpoch));
+ memcpy(hdr.date,buffer,12);
+
+ // Get rid of trailing blanks in the name
+ std::string mbrPath = mbr.getPath().str();
+ size_t mbrLen = mbrPath.length();
+ while (mbrLen > 0 && mbrPath[mbrLen-1] == ' ') {
+ mbrPath.erase(mbrLen-1,1);
+ mbrLen--;
+ }
+
+ // Set the name field in one of its various flavors.
+ bool writeLongName = false;
+ if (mbr.isStringTable()) {
+ memcpy(hdr.name,ARFILE_STRTAB_NAME,16);
+ } else if (mbr.isSVR4SymbolTable()) {
+ memcpy(hdr.name,ARFILE_SVR4_SYMTAB_NAME,16);
+ } else if (mbr.isBSD4SymbolTable()) {
+ memcpy(hdr.name,ARFILE_BSD4_SYMTAB_NAME,16);
+ } else if (mbr.isLLVMSymbolTable()) {
+ memcpy(hdr.name,ARFILE_LLVM_SYMTAB_NAME,16);
+ } else if (TruncateNames) {
+ const char* nm = mbrPath.c_str();
+ unsigned len = mbrPath.length();
+ size_t slashpos = mbrPath.rfind('/');
+ if (slashpos != std::string::npos) {
+ nm += slashpos + 1;
+ len -= slashpos +1;
+ }
+ if (len > 15)
+ len = 15;
+ memcpy(hdr.name,nm,len);
+ hdr.name[len] = '/';
+ } else if (mbrPath.length() < 16 && mbrPath.find('/') == std::string::npos) {
+ memcpy(hdr.name,mbrPath.c_str(),mbrPath.length());
+ hdr.name[mbrPath.length()] = '/';
+ } else {
+ std::string nm = "#1/";
+ nm += utostr(mbrPath.length());
+ memcpy(hdr.name,nm.data(),nm.length());
+ if (sz < 0)
+ sz -= mbrPath.length();
+ else
+ sz += mbrPath.length();
+ writeLongName = true;
+ }
+
+ // Set the size field
+ if (sz < 0) {
+ buffer[0] = '-';
+ sprintf(&buffer[1],"%-9u",(unsigned)-sz);
+ } else {
+ sprintf(buffer, "%-10u", (unsigned)sz);
+ }
+ memcpy(hdr.size,buffer,10);
+
+ return writeLongName;
+}
+
+// Insert a file into the archive before some other member. This also takes care
+// of extracting the necessary flags and information from the file.
+bool
+Archive::addFileBefore(const sys::Path& filePath, iterator where,
+ std::string* ErrMsg) {
+ bool Exists;
+ if (sys::fs::exists(filePath.str(), Exists) || !Exists) {
+ if (ErrMsg)
+ *ErrMsg = "Can not add a non-existent file to archive";
+ return true;
+ }
+
+ ArchiveMember* mbr = new ArchiveMember(this);
+
+ mbr->data = 0;
+ mbr->path = filePath;
+ const sys::FileStatus *FSInfo = mbr->path.getFileStatus(false, ErrMsg);
+ if (!FSInfo) {
+ delete mbr;
+ return true;
+ }
+ mbr->info = *FSInfo;
+
+ unsigned flags = 0;
+ bool hasSlash = filePath.str().find('/') != std::string::npos;
+ if (hasSlash)
+ flags |= ArchiveMember::HasPathFlag;
+ if (hasSlash || filePath.str().length() > 15)
+ flags |= ArchiveMember::HasLongFilenameFlag;
+
+ sys::fs::file_magic type;
+ if (sys::fs::identify_magic(mbr->path.str(), type))
+ type = sys::fs::file_magic::unknown;
+ switch (type) {
+ case sys::fs::file_magic::bitcode:
+ flags |= ArchiveMember::BitcodeFlag;
+ break;
+ default:
+ break;
+ }
+ mbr->flags = flags;
+ members.insert(where,mbr);
+ return false;
+}
+
+// Write one member out to the file.
+bool
+Archive::writeMember(
+ const ArchiveMember& member,
+ std::ofstream& ARFile,
+ bool CreateSymbolTable,
+ bool TruncateNames,
+ std::string* ErrMsg
+) {
+
+ unsigned filepos = ARFile.tellp();
+ filepos -= 8;
+
+ // Get the data and its size either from the
+ // member's in-memory data or directly from the file.
+ size_t fSize = member.getSize();
+ const char *data = (const char*)member.getData();
+ MemoryBuffer *mFile = 0;
+ if (!data) {
+ OwningPtr<MemoryBuffer> File;
+ if (error_code ec = MemoryBuffer::getFile(member.getPath().c_str(), File)) {
+ if (ErrMsg)
+ *ErrMsg = ec.message();
+ return true;
+ }
+ mFile = File.take();
+ data = mFile->getBufferStart();
+ fSize = mFile->getBufferSize();
+ }
+
+ // Now that we have the data in memory, update the
+ // symbol table if it's a bitcode file.
+ if (CreateSymbolTable && member.isBitcode()) {
+ std::vector<std::string> symbols;
+ std::string FullMemberName = archPath.str() + "(" + member.getPath().str()
+ + ")";
+ Module* M =
+ GetBitcodeSymbols(data, fSize, FullMemberName, Context, symbols, ErrMsg);
+
+ // If the bitcode parsed successfully
+ if ( M ) {
+ for (std::vector<std::string>::iterator SI = symbols.begin(),
+ SE = symbols.end(); SI != SE; ++SI) {
+
+ std::pair<SymTabType::iterator,bool> Res =
+ symTab.insert(std::make_pair(*SI,filepos));
+
+ if (Res.second) {
+ symTabSize += SI->length() +
+ numVbrBytes(SI->length()) +
+ numVbrBytes(filepos);
+ }
+ }
+ // We don't need this module any more.
+ delete M;
+ } else {
+ delete mFile;
+ if (ErrMsg)
+ *ErrMsg = "Can't parse bitcode member: " + member.getPath().str()
+ + ": " + *ErrMsg;
+ return true;
+ }
+ }
+
+ int hdrSize = fSize;
+
+ // Compute the fields of the header
+ ArchiveMemberHeader Hdr;
+ bool writeLongName = fillHeader(member,Hdr,hdrSize,TruncateNames);
+
+ // Write header to archive file
+ ARFile.write((char*)&Hdr, sizeof(Hdr));
+
+ // Write the long filename if its long
+ if (writeLongName) {
+ ARFile.write(member.getPath().str().data(),
+ member.getPath().str().length());
+ }
+
+ // Write the (possibly compressed) member's content to the file.
+ ARFile.write(data,fSize);
+
+ // Make sure the member is an even length
+ if ((ARFile.tellp() & 1) == 1)
+ ARFile << ARFILE_PAD;
+
+ // Close the mapped file if it was opened
+ delete mFile;
+ return false;
+}
+
+// Write out the LLVM symbol table as an archive member to the file.
+void
+Archive::writeSymbolTable(std::ofstream& ARFile) {
+
+ // Construct the symbol table's header
+ ArchiveMemberHeader Hdr;
+ Hdr.init();
+ memcpy(Hdr.name,ARFILE_LLVM_SYMTAB_NAME,16);
+ uint64_t secondsSinceEpoch = sys::TimeValue::now().toEpochTime();
+ char buffer[32];
+ sprintf(buffer, "%-8o", 0644);
+ memcpy(Hdr.mode,buffer,8);
+ sprintf(buffer, "%-6u", sys::Process::GetCurrentUserId());
+ memcpy(Hdr.uid,buffer,6);
+ sprintf(buffer, "%-6u", sys::Process::GetCurrentGroupId());
+ memcpy(Hdr.gid,buffer,6);
+ sprintf(buffer,"%-12u", unsigned(secondsSinceEpoch));
+ memcpy(Hdr.date,buffer,12);
+ sprintf(buffer,"%-10u",symTabSize);
+ memcpy(Hdr.size,buffer,10);
+
+ // Write the header
+ ARFile.write((char*)&Hdr, sizeof(Hdr));
+
+#ifndef NDEBUG
+ // Save the starting position of the symbol tables data content.
+ unsigned startpos = ARFile.tellp();
+#endif
+
+ // Write out the symbols sequentially
+ for ( Archive::SymTabType::iterator I = symTab.begin(), E = symTab.end();
+ I != E; ++I)
+ {
+ // Write out the file index
+ writeInteger(I->second, ARFile);
+ // Write out the length of the symbol
+ writeInteger(I->first.length(), ARFile);
+ // Write out the symbol
+ ARFile.write(I->first.data(), I->first.length());
+ }
+
+#ifndef NDEBUG
+ // Now that we're done with the symbol table, get the ending file position
+ unsigned endpos = ARFile.tellp();
+#endif
+
+ // Make sure that the amount we wrote is what we pre-computed. This is
+ // critical for file integrity purposes.
+ assert(endpos - startpos == symTabSize && "Invalid symTabSize computation");
+
+ // Make sure the symbol table is even sized
+ if (symTabSize % 2 != 0 )
+ ARFile << ARFILE_PAD;
+}
+
+// Write the entire archive to the file specified when the archive was created.
+// This writes to a temporary file first. Options are for creating a symbol
+// table, flattening the file names (no directories, 15 chars max) and
+// compressing each archive member.
+bool
+Archive::writeToDisk(bool CreateSymbolTable, bool TruncateNames,
+ std::string* ErrMsg)
+{
+ // Make sure they haven't opened up the file, not loaded it,
+ // but are now trying to write it which would wipe out the file.
+ if (members.empty() && mapfile && mapfile->getBufferSize() > 8) {
+ if (ErrMsg)
+ *ErrMsg = "Can't write an archive not opened for writing";
+ return true;
+ }
+
+ // Create a temporary file to store the archive in
+ sys::Path TmpArchive = archPath;
+ if (TmpArchive.createTemporaryFileOnDisk(ErrMsg))
+ return true;
+
+ // Make sure the temporary gets removed if we crash
+ sys::RemoveFileOnSignal(TmpArchive);
+
+ // Create archive file for output.
+ std::ios::openmode io_mode = std::ios::out | std::ios::trunc |
+ std::ios::binary;
+ std::ofstream ArchiveFile(TmpArchive.c_str(), io_mode);
+
+ // Check for errors opening or creating archive file.
+ if (!ArchiveFile.is_open() || ArchiveFile.bad()) {
+ TmpArchive.eraseFromDisk();
+ if (ErrMsg)
+ *ErrMsg = "Error opening archive file: " + archPath.str();
+ return true;
+ }
+
+ // If we're creating a symbol table, reset it now
+ if (CreateSymbolTable) {
+ symTabSize = 0;
+ symTab.clear();
+ }
+
+ // Write magic string to archive.
+ ArchiveFile << ARFILE_MAGIC;
+
+ // Loop over all member files, and write them out. Note that this also
+ // builds the symbol table, symTab.
+ for (MembersList::iterator I = begin(), E = end(); I != E; ++I) {
+ if (writeMember(*I, ArchiveFile, CreateSymbolTable,
+ TruncateNames, ErrMsg)) {
+ TmpArchive.eraseFromDisk();
+ ArchiveFile.close();
+ return true;
+ }
+ }
+
+ // Close archive file.
+ ArchiveFile.close();
+
+ // Write the symbol table
+ if (CreateSymbolTable) {
+ // At this point we have written a file that is a legal archive but it
+ // doesn't have a symbol table in it. To aid in faster reading and to
+ // ensure compatibility with other archivers we need to put the symbol
+ // table first in the file. Unfortunately, this means mapping the file
+ // we just wrote back in and copying it to the destination file.
+ sys::Path FinalFilePath = archPath;
+
+ // Map in the archive we just wrote.
+ {
+ OwningPtr<MemoryBuffer> arch;
+ if (error_code ec = MemoryBuffer::getFile(TmpArchive.c_str(), arch)) {
+ if (ErrMsg)
+ *ErrMsg = ec.message();
+ return true;
+ }
+ const char* base = arch->getBufferStart();
+
+ // Open another temporary file in order to avoid invalidating the
+ // mmapped data
+ if (FinalFilePath.createTemporaryFileOnDisk(ErrMsg))
+ return true;
+ sys::RemoveFileOnSignal(FinalFilePath);
+
+ std::ofstream FinalFile(FinalFilePath.c_str(), io_mode);
+ if (!FinalFile.is_open() || FinalFile.bad()) {
+ TmpArchive.eraseFromDisk();
+ if (ErrMsg)
+ *ErrMsg = "Error opening archive file: " + FinalFilePath.str();
+ return true;
+ }
+
+ // Write the file magic number
+ FinalFile << ARFILE_MAGIC;
+
+ // If there is a foreign symbol table, put it into the file now. Most
+ // ar(1) implementations require the symbol table to be first but llvm-ar
+ // can deal with it being after a foreign symbol table. This ensures
+ // compatibility with other ar(1) implementations as well as allowing the
+ // archive to store both native .o and LLVM .bc files, both indexed.
+ if (foreignST) {
+ if (writeMember(*foreignST, FinalFile, false, false, ErrMsg)) {
+ FinalFile.close();
+ TmpArchive.eraseFromDisk();
+ return true;
+ }
+ }
+
+ // Put out the LLVM symbol table now.
+ writeSymbolTable(FinalFile);
+
+ // Copy the temporary file contents being sure to skip the file's magic
+ // number.
+ FinalFile.write(base + sizeof(ARFILE_MAGIC)-1,
+ arch->getBufferSize()-sizeof(ARFILE_MAGIC)+1);
+
+ // Close up shop
+ FinalFile.close();
+ } // free arch.
+
+ // Move the final file over top of TmpArchive
+ if (FinalFilePath.renamePathOnDisk(TmpArchive, ErrMsg))
+ return true;
+ }
+
+ // Before we replace the actual archive, we need to forget all the
+ // members, since they point to data in that old archive. We need to do
+ // this because we cannot replace an open file on Windows.
+ cleanUpMemory();
+
+ if (TmpArchive.renamePathOnDisk(archPath, ErrMsg))
+ return true;
+
+ // Set correct read and write permissions after temporary file is moved
+ // to final destination path.
+ if (archPath.makeReadableOnDisk(ErrMsg))
+ return true;
+ if (archPath.makeWriteableOnDisk(ErrMsg))
+ return true;
+
+ return false;
+}
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